The proposal to cut the US strategic warhead arsenal by up 40pc could save billions of dollars and take America another step closer to the long-term goal – avowed by Mr Obama in his landmark speech in Prague in 2009 – of a nuclear-free world.

Although Mr Obama, left, is not expected to give precise numbers in his speech, reports yesterday claimed that the number of warheads could be cut from 1,700 to as low as 1,000, if a mutual agreement can be secured with Russia.

Mr Obama believes that "pretty radical reductions" can be made to the arsenal, a left-over from the Cold War, and US military leaders have "signed off" on the proposed reductions.

"These numbers ring true," Steven Pifer, a former State Department official and director of the Arms Control Initiative at the Brookings Institution said.

Under the current New START treaty, the US and Russia have agreed to cut strategic warheads to 1,550 by early 2018, but Mr Obama's proposals would significantly accelerate that process.